Tag Archives: Series 70 vs Series 80

On Monday I posted an initial look at theColt Mk. IV Series 70 — a current version from Colt’s Custom Shop. In that article I explained how the Series 70 came about, how the Series 70 firing system differs from the Series 80 system used in Colt M1911 pistols since 1983, and why Colt reintroduced the Series 70 in limited runs beginning in 2001.

Colt Mk. IV Series 70 (stainless); Colt M1991A1 (blue)

In the M1911 world, there is a persistent, often repeated claim that the Series 70 firing system results in a superior trigger to the much maligned Series 80 system. But does this claim hold validity when put to the test?

Mk. IV Series 70 versus M1991A1 Series 80

To find out I took a new, fresh from the box Colt Mk. IV Series 70 .45 ACP and directly compared the trigger to three Series 80 pistols. The video below shows how the Series 70 stacked up against a blued, 2014-vintage Colt M1991A1 Series 80 .45 ACP. Not in the video — but also used in comparison — were two unfired Colt M1991A1 Series 80 pistols. One is another blued .45 ACP identical to the test pistol but of slightly later vintage; the other is stainless and chambered in .38 Super +P (see: Stainless Colt .38 Super +P M1991A1 — How do you go bankrupt making something this good?). Here are all four Colts posing for a family portrait:

Colt Mk. IV Series 70 swimming against school of M1991A1

This was a pretty simple test of triggers, and admittedly perhaps a bit subjective as I used no measuring equipment in this test. On each cocked weapon I depressed the grip safety, took up the trigger slack, and then slowly and carefully squeezed the trigger until the sear tripped and the hammer fell. I took video of the first test, which pitted the Mk. IV Series 70 against the aforementioned M1991A1. This particular M1991A1 has perhaps 100 rounds of .45 ACP through it, so break-in shouldn’t have been a factor. The results of this test were thus:

I was pretty shocked at the results of this comparison. I previously reviewed the M1991A1 used in the above video (see: A 1911 by Any Other Name Would Be . . . an M1991A1 — Shooting Review), so I already knew that the Series 80 trigger is one of the best I’ve ever encountered in a semiautomatic. In that article I said of the Series 80 firing pin block and the reported effect on the trigger:

That last Series 80 feature is a bit controversial. Some claim that it unnecessarily complicated the original design, degraded the trigger by making it stiffer and adding an almost imperceptible (in my view) amount of trigger creep before the hammer trips, and gunsmiths complained that the new design is more difficult to tune to competition standards. My personal opinion? It’s still one of the best triggers out there, and according to my research any gunsmith worthy of the title will be able to tune your trigger with just a bit more effort. But even out of the box, I’d be hard pressed to understand why anyone would think this weapon needs any tuning whatsoever. If the shooter can’t hold this weapon on target, then it’s the shooter who has a problem rather than the trigger and firing system on this weapon.

Still, after having read so many Colt M1911 purists touting the Series 70’s superiority, I thought there was a chance that this particular M1991A1 was perhaps exceptional. I was wrong. Compared to the two additional comparisons I ran on the second and third unfired M1991A1 pistols, the one with some rounds through it wasn’t even quite as good. Darn close, mind you, but it has just a hint of creep between slack take-up and sear trip. The other pistols had none . . . at least none that I could feel, and the .38 Super +P was the best of the lot as the trigger was noticeably lighter than either of the other two Series 80 pistols or the Mk. IV Series 70.

Is three against one fair fight? Apparently not!

Incredibly, the Mk. IV Series 70 was the worst of the lot. But even the worst M1911 trigger bests pretty much anything else out there in the semiautomatic world. From the descriptions I’ve read of the Series 80 trigger I expected all three would in comparison be stiffer, display more creep, and exhibit at least a degree of grittiness. But this wasn’t the case on two of the Series 80s, and on the third the ever-so-slight trigger creep and any “grittiness” were noticeably less than that of the Series 70. In quantifiable terms, the Series 70 crept for between ⅛ to ¼ inch (3.2mm to 6.3mm) from slack take-up to sear trip, and there was a faintly detectable grittiness to the feel. The M1991A1 in the video in comparison had less than ⅛ inch creep (in other words, nearly none), and no grittiness in the feel of the trigger.

The Series 80 Competition

So, is the Mk. IV Series 70 from Colt’s Custom Shop worth the price premium over a Series 80 M1991A1, or even the slightly more expensive Series 80 M1911A1? Not if you’re looking for a better out-of-the-box trigger, because this isn’t it.

Is the Mk. IV Series 70 worth the premium to round out a Colt Collection? Probably. If you can get the price down from the MSRP. This is especially the case now that Colt have reduced the MSRP on the M1991A1. When I first reviewed the M1991A1 the MSRP was $974, and the pistol reviewed was purchased for $950. Now MSRP on the M1991A1 is $799, and the unfired example in today’s post was snagged for $775. The somewhat rare stainless chambered in .38 Super +P cost $900 back in June.

In comparison, MSRP for the Mk. IV Series 70 is $979 (at the time of this writing), but it seems prices are falling since the purchase of this example for a buck more than the MSRP (and some $200 less than the gun store was originally asking because of its exclusive, hard-to-get nature). Probably because of Colt’s recent excursion into bankruptcy, you can find Mk. IV Series 70 pistols at online gun stores for well south of $900, and is some cases even below the $850 mark. That makes this a good time to add one to the collection, as these pistols were going from several hundreds of dollars more just a few months ago before Colt’s recent bankruptcy announcement.

This week we’re taking a break from travel and photography and concentrating on another of my varied areas of interest — firearms. We’ll begin with a rather rare bird, a new Colt Mk. IV Series 70. The example you see here is in stainless steel.

But first a history lesson on the Colt “Government Model” M1911 Series 70 versus the Series 80, and the controversy surrounding the latter.

Colt’s Custom Shop Mk. IV Series 70 in stainless

The Mk. IV Series 70 dates from the year 1970. It differed from the previous M1911A1 (1924) in that the pistol had installed a split barrel bushing (sometimes referred to as a “collet bushing”) to increase accuracy of an already very accurate handgun. The following photos from Hooper Gun Works illustrate the difference between the two bushings. The first show the differing bushings installed onto a Colt barrel, and the second is a close-up of the actual bushings:

To be brutally frank about it, the split barrel “collet” bushing was a bit of a disaster. The fingers had a tendency to break off and jam the pistol. So, by 1988 the split barrel bushing gave way to a return to the solid bushing in later iterations of the Colt M1911 line.

Colt Mk IV roll mark

Colt ended the Mk. IV Series 70 in 1983 with the introduction of the Series 80. This M1911 initially retained the split barrel bushing, but it incorporated a new feature hated by M1911 purists. It is theoretically possible that if a cocked-and-locked M1911 is dropped onto a hard surface in such a way that the muzzle strikes first, the free-floating firing pin may have enough inertia to overcome the tension of the firing pin spring and thus impact the bullet primer. This could produce an unintended discharge.

M1991A1 roll mark

Colt addressed this concern in 1983 by redesigning the firing system to incorporate a firing pin block. The firing pin block is disengaged by the trigger mechanism as the trigger is pulled. So, why the controversy among 1911 purists? After all, isn’t increased firearm safety a good thing?

Apparently, not if it adversely impacts a great single-action trigger . . . or even if it’s merely imagined to do so.

Mk IV reverse side

Many claim that this trigger-deactivated firing pin block increased trigger weight and friction. I’ll be testing this claim on Wednesday with a video of a test I performed that pits the Mk. IV Series 70 pictured here up against a Colt M1991A1 with the so-called Series 80 trigger. Not in the video but outlined in the text on Wednesday are additional comparisons I performed with a stainless Colt M1991A1 chambered in .38 Super and another .45 ACP Colt M1991A1 identical to the one used in the video. I believe you’ll find the results most enlightening, and I’m sure very controversial among M1911 purists.

M1991A1 reverse side

By now you’re asking, how the heck did Series 70 come to mean a trigger that dates from 1911 to 1983, while Series 80 describes the trigger system with a firing pin block incorporated in 1983? Good question, since the Series 70 was so designated not because of the trigger system, but rather because of the split barrel “collet” bushing — a bushing that continued on in the Series 80 pistol for some five years. The answer is convenience. It’s just easier to differentiate between the original internal trigger design of the M1911 to the later firing pin block design by referring to the two designs as “Series 70” and “Series 80” firing systems.

Here is another photo from Hooper Gun Works that illustrates one of the modifications made, in this case to the hammer:

Notched Series 70 hammer on left; shelved Series 80 hammer on right

(Note:There is a competing firing pin block design out there for the M1911 in which the firing pin block is deactivated by the grip safety rather than the trigger. It’s called the Swartz Firing Pin Safety, and it’s used by some competing M1911 producers such as Kimber and Smith & Wesson. Ironically, Colt pioneered the Swartz system in 1938, but dropped it after only three years because the U.S. military balked at the added expense, as did the civilian market. Modern manufacturing processes have allowed the economical reintroduction of the Swartz system, but Colt have stuck with the Series 80 firing system.)

Around the turn of the century it began to dawn on Colt that M1911 purists were leaving the fold for competing M1911s produced without the “trigger degrading” Series 80 firing pin block. This resulted in Colt reintroducing a “Mk. IV Series 70” that really isn’t much like the one produced from 1970 to 1983. For one thing, there was no return to the split barrel bushing. The Series 80 slide and frame were also retained, even if the firing pin block was removed. Of interest to some may be the fact that Colt continues to use in the reintroduced Series 70 the internals of the Series 80. That means the shelved hammer pictured above is still used rather than the earlier notched hammer. What Colt is giving you with the new Mk. IV Series 70 is in fact a Series 80 pistol with Series 80 trigger system parts, only without the actual firing pin block. This removes from the trigger-feel equation the internal movement that disengages the firing pin block.

Well, there is one other difference. The new Mk. IV Series 70 is produced in very limited runs in the Colt Custom Shop. That means if you find one, you’re laying your hands fairly rare pistol. My source puts the annual production numbers of Colt Custom Shop Mk. IV Series 70s at between 500 and 1,000. Additionally, as these pistols originate from the Custom Shop, they ship in the famous blue “Colt Custom Shop” box, which alone is worth probably north of a hundred bucks.

Standard Colt plastic case next to Colt Custom Shop box

Colt Mk. IV Series 70

Colt M1991A1

Colt Custom Shop close-up

Now let’s compare a Mk. IV Series 70 to an M1991A1 Series 80. Externally they appear much the same. Both are roll marked as “Government Models”. Both have nicely checkered rosewood grips. Finish is equally nice on these two examples, and slide-to-frame fit is exceedingly tight, as is the barrel-to-bushing fit. These are very tight pistols which I personally would not hesitate to put up against pistols costing two and three times as much.

Now for the differences:

The most obvious are the sights. Both pistols come equipped with High-Profile sights, but the M1991A1 sights use the three-dot system while the Mk. IV Series 70 is absent any such visual cue.

Combat sights vs. three-dot sights

Less obvious is the trigger placement. The aluminum M1991A1 trigger is a longish affair protruding almost half way across the span inside the trigger guard. The stainless Mk. IV Series 70 is much shorter in length.

Short Mk. IV Series 70 trigger (top) next to the M1991A1 long trigger

Least obvious of all is the backstrap below the grip safety. Both backstraps are grooved in this area, but the M1991A1 backstrap is straight while the Mk. IV Series 70 backstrap has a slight curve.

On Wednesday we’ll test conventional wisdom and put the Series 70 trigger to the test against the Series 80.

I would like to take this time to acknowledge the fine photo work of Hooper Gun Works, to which I linked in this blog. Hooper probably explain the Series 70 and Series 80 difference better than I, so please give their wonderful article a look as well by clicking on the link below: